Organic electroluminescent element

ABSTRACT

The present invention provides an organic electroluminescent element which comprises: an anode; a cathode; and an organic layer interposed between the anode and the cathodes, wherein the organic layer comprises one or more types of layer from the group consisting of a hole-injection layer, hole-transport layer, light-emitting layer, lifetime enhancement layer, electron-transport layer, and electron-injection layer.

TECHNICAL FIELD

The present invention relates to an organic electroluminescent elementcomprising an organic layer.

BACKGROUND ART

Studies on an electroluminescent (EL) element have led to blueelectroluminescence using a single crystal of anthracene in 1965, andthen, an organic electroluminescent element of a bilayer structureconsisting of a hole layer (NPB) and a light-emitting layer (Alq₃) wasproposed by Tang in 1987. Since then, studies have been directed towardthe implementation of high efficiency and long lifespan inelectroluminescent elements, suggesting a multilayer structurecomprising an organic layer responsible for hole injection or holetransport, an organic layer responsible for electron injection orelectron transport, and an organic layer responsible for combining ahole and an electron to induce electroluminescence. The introduction ofmultilayer structures has improved performance of organicelectroluminescent elements to a level of commercialization. As aresult, starting from radio display products for automobiles in 1997,the application of organic electroluminescence elements has beenexpanded to mobile information display devices and TV displays.

Requirements of enlargement and high resolution for displays areaccompanied by the problems of high efficiency and long lifespan inorganic electroluminescence elements in high resolution displays.Particularly, the high resolution that is achieved by forming morepixels in the same area reduces a luminescent area of organicelectroluminescent elements, incurring a decrease in lifespan. This isone of the most important technical problem to be solved for organicelectroluminescent elements.

In an organic electroluminescent element, the application of a currentor voltage across two opposite electrodes induces the injection of holesfrom the anode and electrons from the cathode into an organic layer. Theinjected holes and electrons recombine with each other to generateexcitons which then return to the ground state, emitting light.According to kinds of electron spin of the excitons formed, the organicelectroluminescent elements may be classified into fluorescentlight-emitting elements in which decay of singlet excitons contributesto the production of light through spontaneous emission andphosphorescent light-emitting elements in which decay of tripletexcitons contributes to the production of light through spontaneousemission.

Electron spin of excitons formed by the recombination of electrons andholes may either be in a singlet state or a triplet state at a ratio of25% singlet state: 75% triplet state. Fluorescent light-emittingelements in which light is emitted by singlet exciton, theoreticallydoes not exceed 25% in internal quantum efficiency and 5% in externalquantum efficiency, based on the formation rate of a singlet excitons.Phosphorescent light-emitting elements in which light is emitted bytriplet exciton exhibits emission efficiency four times as high as thatof fluorescent light-emitting elements.

Although phosphorescent light-emitting elements are higher in emissionefficiency than fluorescent light-emitting elements, as described above,on a theoretical basis, a host that meets the color purity of deep blueand the high efficiency required in blue phosphorescent light-emittingelements is underdeveloped so that blue fluorescent light-emittingelements rather than blue phosphorescent light-emitting elements havepredominantly been employed in products thus far.

Studies for improving properties of organic electroluminescent elementshave reported that the prevention of holes from diffusing into anelectron transport layer contributes to the stability of elements.Materials such as BCP or BPhen have been suggested as a blockingmaterial introduced between a light emission layer and an electrontransport layer to increase the recombination rate of holes andelectrons by preventing the diffusion of holes into the electrontransport layer and by limiting holes within the light emission layer.However, being poor in oxidation stability and thermal durability, thederivatives such as BCP or BPhen were observed to reduce the lifespan oforganic electroluminescent elements, and thus finally failed incommercialization. Further, such materials inhibit the movement ofelectrons to increase the driving voltage of the organicelectroluminescent element.

DISCLOSURE Technical Problem

In order to solve the problems encountered in related art, a purpose ofthe present invention is to provide an organic electroluminescentelement outstanding in terms of driving voltage, emission efficiency,and lifespan.

Technical Solution

In order to accomplish the above purpose thereof, the present inventionprovides an organic electroluminescent element comprising: an anode; acathode; and an organic layer interposed therebetween, wherein theorganic layer comprises a compound represented by the following Formula1:

wherein,

R_(a) and R_(b) are the same or different from each other and are eachindependently selected from the group consisting of a C₁-C₄₀ alkyl groupand a C₆-C₆₀ aryl group, or combine with each other to form a fusedring,

R₁ to R₃ are the same or different from each other and are eachindependently selected from the group consisting of a hydrogen, adeuterium, a halogen, a cyano group, a nitro group, an amino group, aC₁-C₄₀ alkyl group, a C₂-C₄₀ alkenyl group, a C₂-C₄₀ alkynyl group, aC₃-C₄₀ cycloalkyl group, a heterocycloalkyl group having 3 to 40 nuclearatoms, a C₆-C₆₀ aryl group, a heteroaryl group having 5 to 60 nuclearatoms, a C₁-C₄₀ alkyloxy group, a C₆-C₆₀ aryloxy group, a C₁-C₄₀alkylsilyl group, a C₆-C₆₀ arylsilyl group, a C₁-C₄₀ alkylboron group, aC₆-C₆₀ arylboron group, a C₁-C₄₀ phosphine group, a C₁-C₄₀ phosphineoxide group, and a C₆-C₆₀ arylamine group, or each of R₁ to R₃ forms afused ring when combined with an adjacent one,

L is selected from the group consisting of a single bond, a C₆-C₁₈arylene group, and a heteroarylene group having 5 to 18 nuclear atoms,

Z₁ to Z₅ are the same or different from each other and are eachindependently N or C(R₄), provided that at least one of Z₁ to Z₅ is N,and when C(R₄) is present in a plural number, they are the same ordifferent from each other,

c and e are each an integer of 0 to 4,

d is an integer of 0 to 3,

m and n are each an integer of 1 to 3,

R₄ is selected from the group consisting of a hydrogen, a deuterium, ahalogen, a cyano group, a nitro group, an amino group, a C₁-C₄₀ alkylgroup, a C₂-C₄₀ alkenyl group, a C₂-C₄₀ alkynyl group, a C₃-C₄₀cycloalkyl group, a heterocycloalkyl group having 3 to 40 nuclear atoms,a C₆-C₆₀ aryl group, a heteroaryl group having 5 to 60 nuclear atoms, aC₁-C₄₀ alkyloxy group, a C₆-C₆₀ aryloxy group, a C₁-C₄₀ alkylsilylgroup, a C₆-C₆₀ arylsilyl group, a C₁-C₄₀ alkylboron group, a C₆-C₆₀arylboron group, a C₁-C₄₀ phosphine group, a C₁-C₄₀ phosphine oxidegroup and a C₆-C₆₀ arylamine group, or bonded to an adjacent substituentto form a fused ring,

the alkyl and aryl groups of R_(a) and R_(b), the alkyl, alkenyl,alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, alkyloxy,aryloxy, alkylsilyl, arylsilyl, alkylboron, arylboron, phosphine,phosphine oxide, and arylamine groups of R₁ to R₄, and the arylene andheteroarylene groups of L may be each independently unsubstituted orsubstituted with at least one substituent selected from the groupconsisting of a deuterium, a halogen, a cyano group, a nitro group, anamino group, a C₁-C₄₀ alkyl group, a C₂-C₄₀ alkenyl group, a C₂-C₄₀alkynyl group, a C₃-C₄₀ cycloalkyl group, a heterocycloalkyl grouphaving 3 to 40 nuclear atoms, a C₆-C₆₀ aryl group, a heteroaryl grouphaving 5 to 60 nuclear atoms, a C₁-C₄₀ alkyloxy group, a C₆-C₆₀ aryloxygroup, a C₁-C₄₀ alkylsilyl group, a C₆-C₆₀ arylsilyl group, a C₁-C₄₀alkylboron group, a C₆-C₆₀ arylboron group, a C₁-C₄₀ phosphine group, aC₁-C₄₀ phosphine oxide group, and a C₆-C₆₀ arylamine group, providedthat when the substituent is present in a plural number, they are thesame or different from each other.

The compound represented by Formula 1 may be contained in a lifetimeenhancement layer of the organic layer.

Advantageous Effects

As a lifetime enhancement layer, an electron transport layer, or anelectron injection layer all of which comprises a compound havingspecific physical properties is introduced thereinto, an organicelectroluminescent element exhibiting outstanding driving voltage,emission efficiency, and lifespan can be provided.

As the organic electroluminescent element of the present invention isapplied thereto, a display panel improved in performance and lifespancan be provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view illustrating an organicelectroluminescent element according to one embodiment of the presentinvention.

MODE FOR INVENTION

Below, a detailed description is given of the present invention.

An embodiment of the present invention provides an organicelectroluminescent element, comprising an anode; a cathode; and anorganic layer interposed therebetween, wherein the organic layercomprises a compound represented by the following Formula 1:

wherein,

R_(a) and R_(b) are the same or different from each other and are eachindependently selected from the group consisting of a C₁-C₄₀ alkyl groupand a C₆-C₆₀ aryl group, or combine with each other to form a fusedring,

R₁ to R₃ are the same or different from each other and are eachindependently selected from the group consisting of a hydrogen, adeuterium, a halogen, a cyano group, a nitro group, an amino group, aC₁-C₄₀ alkyl group, a C₂-C₄₀ alkenyl group, a C₂-C₄₀ alkynyl group, aC₃-C₄₀ cycloalkyl group, a heterocycloalkyl group having 3 to 40 nuclearatoms, a C₆-C₆₀ aryl group, a heteroaryl group having 5 to 60 nuclearatoms, a C₁-C₄₀ alkyloxy group, a C₆-C₆₀ aryloxy group, a C₁-C₄₀alkylsilyl group, a C₆-C₆₀ arylsilyl group, a C₁-C₄₀ alkylboron group, aC₆-C₆₀ arylboron group, a C₁-C₄₀ phosphine group, a C₁-C₄₀ phosphineoxide group, and a C₆-C₆₀ arylamine group, or each of R₁ to R₃ forms afused ring when combined with an adjacent one (in detail, combinationbetween adjacent R₁'s, between adjacent R₂'s, between adjacent R₃'s, orbetween R₁ and R₂),

L is selected from the group consisting of a single bond, a C₆-C₁₈arylene group, and a heteroarylene group having 5 to 18 nuclear atoms,

Z₁ to Z₅ are the same or different from each other and are eachindependently N or C(R₄), provided that at least one of Z₁ to Z₅ is N,and when C(R₄) is present in a plural number, they are the same ordifferent from each other,

c and e are each an integer of 0 to 4,

d is an integer of 0 to 3,

m and n are each an integer of 1 to 3,

R₄ is selected from the group consisting of a hydrogen, a deuterium, ahalogen, a cyano group, a nitro group, an amino group, a C₁-C₄₀ alkylgroup, a C₂-C₄₀ alkenyl group, a C₂-C₄₀ alkynyl group, a C₃-C₄₀cycloalkyl group, a heterocycloalkyl group having 3 to 40 nuclear atoms,a C₆-C₆₀ aryl group, a heteroaryl group having 5 to 60 nuclear atoms, aC₁-C₄₀ alkyloxy group, a C₆-C₆₀ aryloxy group, a C₁-C₄₀ alkylsilylgroup, a C₆-C₆₀ arylsilyl group, a C₁-C₄₀ alkylboron group, a C₆-C₆₀arylboron group, a C₁-C₄₀ phosphine group, a C₁-C₄₀ phosphine oxidegroup and a C₆-C₆₀ arylamine group, or bonded to an adjacent substituent(in detail, combination between adjacent R₄'s) to form a fused ring,

the alkyl and aryl groups of R_(a) and R_(b), the alkyl, alkenyl,alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, alkyloxy,aryloxy, alkylsilyl, arylsilyl, alkylboron, arylboron, phosphine,phosphine oxide, and arylamine groups of R₁ to R₄, and the arylene andheteroarylene groups of L may be each independently unsubstituted orsubstituted with at least one substituent selected from the groupconsisting of a deuterium, a halogen, a cyano group, a nitro group, anamino group, a C₁-C₄₀ alkyl group, a C₂-C₄₀ alkenyl group, a C₂-C₄₀alkynyl group, a C₃-C₄₀ cycloalkyl group, a heterocycloalkyl grouphaving 3 to 40 nuclear atoms, a C₆-C₆₀ aryl group, a heteroaryl grouphaving 5 to 60 nuclear atoms, a C₁-C₄₀ alkyloxy group, a C₆-C₆₀ aryloxygroup, a C₁-C₄₀ alkylsilyl group, a C₆-C₆₀ arylsilyl group, a C₁-C₄₀alkylboron group, a C₆-C₆₀ arylboron group, a C₁-C₄₀ phosphine group, aC₁-C₄₀ phosphine oxide group, and a C₆-C₆₀ arylamine group, providedthat when the substituent is present in a plural number, they are thesame or different from each other.

FIG. 1 depicts an organic electroluminescent element according to anembodiment of the present invention. According to one embodiment of thepresent invention, the organic electroluminescent element comprises: ananode 100; a cathode 200; and an organic layer 300 interposedtherebetween.

The anode 100 functions to inject holes into the organic layer 300. Thematerial of the anode 100 is not particularly limited, but may be ametal such as vanadium, chromium, copper, zinc, gold, etc.; an alloythereof; a metal oxide such as zinc oxide, indium oxide, indium tinoxide (ITO), and indium zinc oxide (IZO); a combination of metal andoxide such as ZnO:Al or SnO₂:Sb; a conductive polymer such aspolythiophene, poly(3-methylthiophene),poly[3,4-(ethylene-1,2-dioxy)thiophene] (PEDT), polypyrrole,polyaniline, etc.; and carbon black. No particular limitations arefurther imparted to the fabrication method of the anode 100, andnon-limitative examples include applying an anode material on asubstrate made of a silicon wafer, quartz, a glass plate, a metal plate,or a plastic film.

The cathode 200 functions to inject electrons into the organic layer300. Although no particular limitations are imparted thereto,non-limitative examples of a material available for the cathode includemetals such as magnesium, calcium, sodium, potassium, titanium, indium,yttrium, lithium, gadolinium, aluminum, silver, tin, lead, etc; an alloythereof; and multilayer materials such as LiF/Al, LiO₂/Al, etc. Anymethod that is known in the art may be used for the fabrication of thecathode 200 without particular limitations.

As can be seen in FIG. 1, the organic layer 300 may particularly includeat least one selected from the group consisting of a hole injectionlayer 301, a hole transport layer 302, a light-emitting layer 303, alifetime enhancement layer 304, an electron transport layer 305, and anelectron injection layer 306. In view of the characteristics of organicelectroluminescent elements, the organic layer 300 may more particularlyinclude all of the layers.

The hole injection layer 301 and the hole transport layer 302 contributeto the migration of the holes injected from the anode 100 into thelight-emitting layer 303. Materials available for the hole injectionlayer 301 and the hole transport layer 302 are not particularly limitedif they have low hole injection barriers and high hole motility, andnon-limitative examples thereof include arylamine derivatives.

In the light-emitting layer 303, holes and electrons meet each other toform excitons. According to the material of the light-emitting layer303, the light emitted by the organic electroluminescent element isdetermined. The light-emitting layer 303 may contain a host and adopant, and may particularly contains 70 to 99.9% by weight of host and0.1 to 30% by weight of dopant. For blue fluorescence, greenfluorescence or red fluorescence, the light-emitting layer 303 mayparticularly contain a host in an amount of 70 to 99.9% by weight and adopant in an amount of 0.1 to 30% by weight and more particularly a hostin an amount of 80 to 99% by weight and a dopant in an amount of 1 to20% by weight.

No particular limitations are imparted to the host contained in thelight-emitting layer 303 if it is known in the art. Non-limitativeexamples of the host include alkali metal complexes; alkaline earthmetal complexes; and fused aromatic ring derivatives. Particularly,preference is made for a host that can increase the emission efficiencyand lifespan of the organic electroluminescent element, as exemplifiedby aluminum complexes, beryllium complexes, anthracene derivatives,pyrene derivatives, triphenylene derivatives, carbazole derivatives,dibenzofuran derivatives, and dibenzothiophene derivatives.

The dopant contained in the light-emitting layer 303 is not particularlylimited if it is known in the art, and non-limitative examples thereofinclude anthracene derivatives, pyrene derivatives, arylaminederivatives, and iridium (Ir)- or platinum (Pt)-containing metal complexcompounds.

The light-emitting layer 303 may consist of one layer (monolayerstructure) or a plurality of layers (multilayer structure). A multilayerstructure of the light-emitting layer 303 may allow the organicelectroluminescent element to emit light of various colors. Forinstance, when a plurality of light-emitting layers is positionedbetween the hole transport layer 302 and the lifetime enhancement layer304, an organic electroluminescent element can emit light of a mixedcolor. In this regard, the light-emitting layers may be made ofheterogeneous materials. In addition, a multilayer structure of thelight-emitting layer 303, although increasing the driving voltage, makesthe current values constant within the organic electroluminescentelement, thus improving as much the emission efficiency of the organicelectroluminescent element as the number of the light-emitting layers.

As implied in the name thereof, the lifetime enhancement layer 304 aimsto improve the lifespan of the organic electroluminescent element, andis provided between the light-emitting layer 303 and the electrontransport layer 305. No particular limitations are imparted to amaterial of the lifetime enhancement layer 304, and a bipolar compoundthat has both an electron withdrawing group (EWG) with high electronwithdrawing ability and an electron donating group (EDG) with highelectron donating ability may be preferably used. More particularly, thecompound represented by Formula 1 may be used as a material of thelifetime enhancement layer 304.

In detail, the bipolar compound particularly has an ionization potentialof 5.5 eV or higher, more particularly 5.5 to 7.0 eV, and mostparticularly 5.6 to 6.6 eV. Further the bipolar compound particularlyhas an energy gap between HOMO and LUMO (E_(HOMO)−E_(LUMO)) of higherthan 3.0 eV and more particularly 2.8 to 3.8 eV. In addition, thebipolar compound particularly has a triplet energy of 2.3 eV or higher,more particularly 2.3 to 3.5 eV, and most particularly 2.3 to 3.0 eV.Furthermore, the bipolar compound particularly has a gap between singletenergy and triplet energy of less than 0.7 eV and more particularly 0.01to 0.7 eV. Given a compound with an ionization potential of 5.5 eV orhigher, the lifetime enhancement layer 304 can prevent the diffusion ormigration of holes into the electron transport layer 305, thuscontributing to improvement in the lifespan of the organicelectroluminescent element.

As a rule, holes move depending on ionization potential levels in anorganic electroluminescent element. When holes diffuse or move to theelectron transport layer 305 through the light-emitting layer 303,irreversible decomposition is generated by oxidation, resulting in adecrease in the lifespan of the organic electroluminescent element. Insome embodiments of the present invention, however, the presence of thelifetime enhancement layer 304 that comprises a bipolar compound with anionization potential of 5.5 eV or higher prevents holes from diffusingor moving to the electron transport layer 305, improving the lifespan ofthe organic electroluminescent element. That is, holes are blocked bythe high energy barrier of the lifetime enhancement layer 304 and thusremain within the light-emitting layer 303.

If the light-emitting layer 303 is made of a red phosphorescentmaterial, an ionization potential of 5.5 eV or higher may be allowedwithout problems for the bipolar compound contained in the lifetimeenhancement layer 304. On the other hand, the use of a green or bluephosphorescent material may particularly require an ionization potentialof 6.0 eV or higher for the bipolar compound.

In accordance with some particular embodiments, the bipolar compound hasan energy gap between HOMO and LUMO (E_(HOMO)−E_(LUMO)) of higher than3.0 eV, a triplet energy of 2.3 eV or higher, and a gap between singletenergy and triplet energy of less than 0.7 eV. The use of such acompound in the lifetime enhancement layer 304 can prevent the excitonformed in the light-emitting layer 303 from diffusing into the electrontransport layer 305 and can interrupt light emission at an interfacebetween the light-emitting layer 303 and the electron transport layer305. Thanks to the bipolar compound, as a result, the organicelectroluminescent element can be prevented from exhibiting spectrumcolor mixing and can be more stabilized, thus increasing in lifespan.

In one embodiment of the present invention, the bipolar compound bearsboth an electron withdrawing group (EWG) of high electron withdrawingability and an electron donating group (EDG) of high electron donatingability, with spatial separation between respective electron clouds ofHOMO and LUMO. Due to this, the gap between triplet energy and singletenergy (ΔEst) of the compound is as small as less than 0.7 eV, so thatthe compound can have high triplet energy (T1) even when the energy gapbetween HOMO and LUMO (E_(HOMO)−E_(LUMO)) exceeds 3.0 eV.

If the light-emitting layer 303 is made of a red phosphorescentmaterial, a triplet energy of 2.3 eV or higher may be allowed withoutproblems for the bipolar compound contained in the lifetime enhancementlayer 304. On the other hand, the use of a green or a bluephosphorescent material may particularly require a triplet energy of 2.5eV or higher and 2.7 eV or higher, respectively, for the bipolarcompound.

Both the hole mobility and the electron mobility of the bipolar compoundare particularly 1×10⁻⁶ cm²/V·s or higher. The use of the compound inthe lifetime enhancement layer 304 prevents the injection of electronsfrom being delayed compared to the number of the holes injected from theanode 100, thus improving the lifespan of the organic electroluminescentelement.

When an electron-hole imbalance occurs as holes and electrons areinjected in different numbers from the anode 100 and the cathode 200,respectively, an excess of electrons or holes that has not participatedin the formation of excitons through recombination accumulate in thelight-emitting layer 303. The electrons or holes accumulated in thelight-emitting layer 303 interrupt smooth oxidation and reduction in thelight-emitting layer 303 or have a negative influence on adjacentlayers, thus reducing the lifespan of the organic electroluminescentelement.

In contrast, the bipolar compound contained in the lifetime enhancementlayer 304 in accordance with the present invention exhibits a holemotility of 1×10⁻⁶ cm²/V·s or greater at room temperature due to theelectron donating group (EDG) and an electron motility of 1×10⁻⁶cm^(z)/V·s or greater at room temperature due to the electronwithdrawing group (EWG). When used in the lifetime enhancement layer304, such compounds can effectively inject electrons into thelight-emitting layer 303. Like this, the smooth injection of electronsinto the light-emitting layer 303 increases efficiency in the formationof excitons in the light-emitting layer 303, thus prolonging thelifespan of the organic electroluminescent element.

The bipolar compound particularly has a framework in which a fluorenemoiety is bonded to a 6-membered heterocyclic ring through a linker(phenylene, biphenylene or terphenylene). In this context, the bipolarcompound may be a compound represented by Formula 1.

According to one embodiment of the present invention, at least one ofthe lifetime enhancement layer 304, the electron transport layer 305,and the electron injection layer 306 comprises a compound represented byFormula 1.

Further, the compound represented by Formula 1 may be embodied by one ofthe compounds represented by the following Formulas 2 to 4.

wherein,

R_(a), R_(b), R₁ to R₃, Z₁ to Z₅, c, d, and e are each the same asdefined in Formula 1.

In the compound represented by Formula 1 of the present invention, thestructure (substituent) represented by

(* is a site where to bond to L) is particularly embodied by one of thestructures (substituents) represented by the following C-1 to C-15.

wherein,

R₄ is the same as defined in Formula 1 and plural R₄'s are the same ordifferent from each other,

R₅ is selected from the group consisting of a hydrogen, a deuterium, ahalogen, a cyano group, a nitro group, a C₁-C₄₀ alkyl group, a C₂-C₄₀alkenyl group, a C₂-C₄₀ alkynyl group, a C₃-C₄₀ cycloalkyl group, aheterocycloalkyl group having 3 to 40 nuclear atoms, a C₆-C₆₀ arylgroup, a heteroaryl group having 5 to 60 nuclear atoms, a C₆-C₆₀ aryloxygroup, a C₁-C₄₀ alkyloxy group, a C₆-C₆₀ arylamine group, a C₁-C₄₀alkylsilyl group, a C₁-C₄₀ alkylboron group, a C₆-C₆₀ arylboron group, aC₆-C₆₀ arylphosphine group, a C₆-C₆₀ arylphosphine oxide group, and aC₆-C₆₀ arylsilyl group, or bonded to an adjacent substituent (in detail,combination between adjacent R5's or between R₄ and R₅) to form a fusedring,

p is an integer of 1 to 4,

the alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl,heteroaryl, aryloxy, alkyloxy, arylamine, alkylsilyl, alkylboron,arylboron, arylphosphine, arylphosphine oxide and arylsilyl groups of R₅may be each independently unsubstituted or substituted with at least onesubstituent selected from the group consisting of a deuterium, ahalogen, a cyano group, a nitro group, a C₁-C₄₀ alkyl group, a C₂-C₄₀alkenyl group, a C₂-C₄₀ alkynyl group, a C₆-C₆₀ aryl group, a heteroarylgroup having 5 to 60 nuclear atoms, a C₆-C₆₀ aryloxy group, a C₁-C₄₀alkyloxy group, a C₆-C₆₀ arylamine group, a C₃-C₄₀ cycloalkyl group, aheterocycloalkyl group having 3 to 40 nuclear atoms, a C₁-C₄₀ alkylsilylgroup, a C₁-C₄₀ alkylboron group, a C₆-C₆₀ arylboron group, a C₆-C₆₀arylphosphine group, a C₆-C₆₀ arylphosphine oxide group and a C₆-C₆₀arylsilyl group, provided that when the substituent is present in aplural number, they are the same or different from each other.

Here, the structure represented by

is more particularly the structure represented by C-9. In greaterdetail, the compound, represented by Formula 1, of the present inventionmay be those represented by the following Formula 5:

wherein,

R_(a), R_(b), R₁ to R₄, L, c, d, e, m, and n are the same each asdefined in Formula 1. Here, considering properties of organicelectroluminescent elements, R₄'s in the compound represented by Formula5 are particularly the same. That is, identical R₄'s particularly give asymmetrical structure to the compound.

When account is taken of properties of organic electroluminescentelements, R_(a) and R_(b) in the compound represented Formula 1 of thepresent invention are each independently a methyl group or a phenylgroup, or bond each other to form a fused ring represented by

(* is a site where to bond).

In the compound represented by Formula 1, R₁ to R₃ are eachindependently selected from the group consisting of a hydrogen, adeuterium, a C₁-C₄₀ alkyl group, a C₆-C₆₀ aryl group, a heteroaryl grouphaving 5 to 60 nuclear atoms, and a C₆-C₆₀ arylamine group. In addition,m and n are each an integer of 1 to 3, and particularly m is 1 and n is1 or 2.

In the compound represented by Formula 1 of the present invention, L isparticularly a single bond, phenylene group, biphenylene group, orterphenylene group. In detail, the linker L is particularly selectedfrom the group consisting of the structures represented by the followingL-1 to L-9 (* is a site where to bond).

The compounds, represented by Formula 1, of the present invention may befurther embodied by the compounds represented by the following FormulasLE-01 to LE-12:

As used herein, the term “alkyl” refers to a monovalent substituentderived from linear or branched saturated hydrocarbon of 1 to 40 carbonatoms. Examples of the alkyl include, but are not limited to, methyl,ethyl, propyl, isobutyl, sec-butyl, pentyl, iso-amyl, hexyl, and thelike.

As used herein, the term “alkenyl” refers to a monovalent substituentderived from a linear or branched unsaturated hydrocarbon of 2 to 40carbon atoms with one or more carbon-carbon double bonds, as exemplifiedby, but not limited to, vinyl, allyl, isopropenyl, 2-butenyl, and thelike.

As used herein, the term “alkynyl” refers to a monovalent substituentderived from a linear or branched unsaturated hydrocarbon of 2 to 40carbon atoms with at least one carbon-carbon triple bond, as exemplifiedby, but not limited to, ethynyl, 2-propynyl, and the like.

As used herein, the term “aryl” denotes a monovalent substituent derivedfrom an aromatic hydrocarbon of 6 to 60 carbon atoms with a single ringor a combination of two or more rings in which two or more rings maysimply be pendant to each other or fused together. Examples of the arylinclude, but are not limited to, phenyl, naphthyl, phenantryl, anthryl,etc.

As used herein, the term “heteroaryl” denotes a monovalent substituentderived from a mono- or polyheterocyclic aromatic hydrocarbon of 5 to 60nuclear atoms in which at least one, particularly one to three carbonatoms of the ring are substituted by a heteroatom such as N, O, S, orSe. Two or more rings of the heteroaryl, if present, may simply bependant to each other or fused together or to an aryl group. Examples ofheteroaryl include 6-membered monocyclic rings such as pyridyl,pyrazinyl, pyrimidinyl, pyridazinyl, and triazinyl; polycyclic ringssuch as phenoxathienyl, indolizinyl, indolyl, purinyl, quinolyl,benzothiazole, and carbazolyl; 2-furanyl; N-imidazolyl; 2-ixosazolyl;2-pyridinyl; and 2-pyrimidinyl, but are not limited thereto.

As used herein, the term “aryloxy” refers to a monovalent substituentrepresented by RO— wherein R denotes an aryl of 6 to 60 carbon atoms, asexemplified by, but not limited to, phenyloxy, naphthyloxy, diphenyloxy,etc.

As used herein, the term “alkyloxy” refers to a monovalent substituentrepresented by R′O— wherein R′ means an alkyl of 1 to 40 carbon atomsand is construed to include a linear, branched or cyclic structure andexamples of which include, but are not limited to, methoxy, ethoxy,n-propoxy, 1-propoxy, t-butoxy, n-butoxy, pentoxy, etc.

As used herein, the term “arylamine” refers to an amine groupsubstituted with an aryl of 6 to 60 carbon atoms.

As used herein, the term “cycloalkyl” refers to a monovalent substituentderived from a mono- or polycyclic non-aromatic hydrocarbon of 3 to 40carbon atoms, examples of which include cyclopropyl, cyclopentyl,cyclohexyl, norbornyl, and adamantyl, but are not limited thereto.

As used herein, the term “heterocycloalkyl” refers to a monovalentsubstituent derived from a non-aromatic hydrocarbon of 3 to 40 nuclearatoms in which at least one, particularly one to three carbon atoms ofthe ring are substituted by a heteroatom such as N, O, S or Se andexamples of which include morpholinyl, piperazinyl, and the like, butare not limited thereto.

As used herein, the term “alkylsilyl” refers to a silyl groupsubstituted with an alkyl of 1 to 40 carbon atoms, and the term“arylsilyl” refers to a silyl group substituted with an aryl of 5 to 60carbon atoms.

As used herein, the term “fused ring” refers to a fused aliphatic ring,a fused aromatic ring, a fused heteroaliphatic ring, a heteroaromaticring, or a combination thereof.

The compound represented by Formula 1 of the present invention can besynthesized in various manners with reference to the synthesisprocedures of the following Examples.

The electron transport layer 305 and the electron injection layer 306act to migrate electrons injected from cathode 200 into thelight-emitting layer 303. A material for the electron transport layer305 or the electron injection layer 306 is nor particularly limited ifit readily allows electron injection and is of large electron motility.Non-limitative examples of the material include compounds represented byFormula 1, anthracene derivatives, heteroaromatic compounds, and alkalimetal complexes.

In detail, the electron transport layer 305 and/or the electroninjection layer 306 is particularly made of the same material as thelifetime enhancement layer 304, that is, a compound represented byFormula 1. In addition, the electron transport layer 305 and/or theelectron injection layer 306 may be co-deposited with alkali metalcomplexes so as to facilitate the injection of electrons from thecathode. The alkali metal complexes may be based on alkali metals,alkaline earth metals, or rare earth metals.

The organic layer according to one embodiment of the present inventionmay further comprise an organic film layer (not shown), disposed betweenthe hole transport layer 302 and the light emitting layer 303, forblocking electrons and excitons. The organic film layer is provided witha high LUMO value so as to block the migration of electrons into thehole transport layer 302 and with high triplet energy so as to preventthe excitons of the light-emitting layer 303 into the hole transportlayer 302. No particular limitations are imparted to the material forthe organic film layer, and non-limitative examples of the materialinclude carbazole derivatives and arylamine derivatives.

The preparation method of the organic layer 300 according to oneembodiment of the present invention is not particularly limited, and maybe a vacuum evaporation method or a solution coating method as anon-limitative example. Examples of the solution coating method includespin coating, dip coating, doctor blading, inkjet printing, and athermal transfer method.

The organic electroluminescent element according to some embodiments ofthe present invention has a structure in which the anode 100, an organiclayer 300, and a cathode 200 are sequentially deposited, and may furthercomprise an insulating layer or an adhesive layer between the anode 100and the organic layer 300 or between the cathode 200 and the organiclayer 300. When a voltage and current is applied thereto, the organicelectroluminescent element can prolong the time taken for initialluminance to decrease half (life time) while maintaining the maximumemission efficiency, so that the organic electroluminescent elementexhibits excellent lifespan properties.

The present invention will be in greater detail described through thefollowing examples that are set forth to illustrate, but are not to beconstrued as limiting the present invention.

Preparation Examples 1 to 12: Preparation of Compounds LE-01 to LE-12

Compounds represented by the following LE-01 to LE-12 were prepared asbipolar compounds useful in the present invention and were measured forΔEst, triplet energy, ionization potential, E_(HOMO)−E_(LUMO), electronmotility, and hole motility, using methods known in the art, and theresults are summarized in Table 1, below.

TABLE 1 Calculated (B3LYP/6 − 31G*) ΔEst Measured (S1 − TripletIonization E_(HOMO) − Electron Hole Cpd. T1) energy potential E_(LUMO)motility motility LE- 0.42 2.78 5.92 3.49 6.8 × 10⁻⁴ 7.3 × 10⁻⁵ 01 LE-0.52 2.68 5.88 3.45 7.3 × 10⁻⁴ 5.9 × 10⁻⁵ 02 LE- 0.47 2.71 5.93 3.56 8.1× 10⁻⁴ 7.6 × 10⁻⁵ 03 LE- 0.57 2.73 6.12 3.44 6.6 × 10⁻⁴ 5.8 × 10⁻⁵ 04LE- 0.51 2.81 5.97 3.63 7.3 × 10⁻⁴ 8.3 × 10⁻⁵ 05 LE- 0.48 2.83 6.16 3.646.8 × 10⁻⁴ 7.6 × 10⁻⁵ 06 LE- 0.49 2.82 5.97 3.60 7.8 × 10⁻⁴ 8.1 × 10⁻⁵07 LE- 0.55 2.80 5.96 3.58 7.9 × 10⁻³ 7.8 × 10⁻⁵ 08 LE- 0.52 2.82 6.013.62 7.3 × 10⁻⁴ 7.7 × 10⁻⁵ 09 LE- 0.47 2.72 5.89 3.45 8.5 × 10⁻⁴ 7.4 ×10⁻⁵ 10 LE- 0.38 2.65 5.87 3.41 6.7 × 10⁻⁴ 6.8 × 10⁻⁵ 11 LE- 0.41 2.716.01 3.51 7.7 × 10⁻⁴ 7.6 × 10⁻⁵ 12 *For hole motility and electronmotility, a film 1 μm thick, made of the bipolar compound, was measuredfor the transit time of carriers.

Examples 1 to 12: Fabrication of Blue Fluorescent Organic Light-EmittingElement

A glass substrate coated with an ITO (indium tin oxide) thin film 1500 Åthick was cleansed by ultrasonication in distilled water and then in asolvent such as isopropyl alcohol, acetone, methanol, etc. and thendried. The glass substrate was transferred to a UV OZONE cleaner (Powersonic 405, Hwashin Tech) and cleaned for 5 min using UV, and transferredto a vacuum evaporator.

On the transparent ITO electrode (substrate) thus obtained, a holeinjection layer, a hole transport layer, a light-emitting layer, alifetime enhancement layer, an electron transport layer, an electroninjection layer, and a cathode were deposited in that order to fabricateorganic electroluminescent elements. Structures of the fabricatedelements are as shown in Table 2, below.

TABLE 2 Hole Hole Light- Lifetime Electron injection transport emittingEnhancement transport layer layer layer Layer layer Cathode Cpd. DS-205NPB AND +5% DS- LE-01 to Alq₃ Al (Doosan 405 LE-12 Corporation) (DoosanCorporation) Thick. 80 nm 15 nm 30 nm 5 nm 25 nm 200 nm

The structures of NPB, AND, and Alq₃ listed in Table 2 are as follows.

Comparative Example 1: Fabrication of Blue Fluorescent OrganicLight-Emitting Element

An element was fabricated in the same manner as in Example 1, with theexception that an electron transport layer 30 nm thick was vapordeposited without employing a lifetime enhancement layer.

Comparative Example 2: Fabrication of Blue Fluorescent OrganicLight-Emitting Element

An element was fabricated in the same manner as in Example 1, with theexception of using the following BCP instead of LE-01.

Experimental Example 1

The elements fabricated in Examples 1 to 12 and Comparative Examples 1and 2 were measured for driving voltage at a current density of 10mA/cm², current efficiency, emitting peak, and lifetime (T₉₇), and theresults are summarized in Table 3, below.

TABLE 3 Driving Current Emitting Volt. Efficiency Peak Lifespan Cpd. (V)(cd/A) (nm) (hr, T₉₇) Example LE- 4.3 7.1 458 63 1 01 Example LE- 4.26.9 458 59 2 02 Example LE- 4.6 7.0 457 62 3 03 Example LE- 4.1 7.3 45858 4 04 Example LE- 4.0 8.0 458 41 5 05 Example LE- 4.2 7.9 458 38 6 06Example LE- 3.8 8.2 458 42 7 07 Example LE- 3.9 8.3 457 35 8 08 ExampleLE- 4.1 7.8 458 39 9 09 Example LE- 4.2 7.9 458 64 10 10 Example LE- 4.57.0 458 75 11 11 Example LE- 4.3 7.4 457 69 12 12 C. — 4.7 5.6 458 32Example 1 C. BCP 5.3 5.9 458 28 Example 2 *For lifespan, a measurementwas made of time taken for luminance to decrease to 97% of the initialvalue thereof, using a lifetime test system (McScience).

As is understood from the data of Table 3, the organicelectroluminescent elements of Examples 1 to 12, each comprising alifetime enhancement layer in accordance with the present invention,were observed to be superior to those of Comparative Examples 1 and 2 interms of current efficiency, driving voltage and lifespan.

Examples 13 to 20: Fabrication of Green Phosphorescent OrganicLight-Emitting Element

A glass substrate coated with an ITO (indium tin oxide) thin film 1500 Åthick was cleansed by ultrasonication in distilled water and then in asolvent such as isopropyl alcohol, acetone, methanol, etc. and thendried. The glass substrate was transferred to a UV OZONE cleaner (Powersonic 405, Hwashin Tech) and cleaned for 5 min using UV, and transferredto a vacuum evaporator.

On the transparent ITO electrode (substrate) thus obtained, a holeinjection layer, a hole transport layer, a light-emitting layer, alifetime enhancement layer, an electron transport layer, an electroninjection layer, and a cathode were deposited in that order to fabricateorganic electroluminescent elements. Structures of the fabricatedelements are as shown in Table 4, below.

TABLE 4 Hole Hole Light- Lifetime Electron Electron injection transportEmitting Enhancement transport injection layer layer layer Layer layerlayer Cathode Cpd. m-MTDATA TCTA CBP + 10% as shown in Alq₃ LiF AlIr(ppy)₃ Table 5, below Thick. 60 nm 80 nm 30 nm 5 nm 25 nm 1 nm 200 nm

The structures of m-MTDATA, TCTA, Ir(ppy)₃, and CBP listed in Table 4are as follows.

Comparative Example 3: Fabrication of Green Phosphorescent OrganicLight-Emitting Element

An element was fabricated in the same manner as in Example 1, with theexception that an electron transport layer 30 nm thick was vapordeposited without employing a lifetime enhancement layer.

Comparative Example 4: Fabrication of Green Phosphorescent OrganicLight-Emitting Element

An element was fabricated in the same manner as in Example 13, with theexception of using the following BCP instead of LE-01.

Experimental Example 2

The elements fabricated in Examples 13 to 20 and Comparative Examples 3and 4 were measured for driving voltage at a current density of 10mA/cm², current efficiency, emitting peak, and lifetime (T₉₇), and theresults are summarized in Table 5, below.

TABLE 5 Driving Current Emitting Volt. Efficiency Peak Lifespan Cpd. (V)(cd/A) (nm) (hr, T₉₇) Example LE- 6.4 37.0 516 51 13 01 Example LE- 6.138.8 516 53 14 02 Example LE- 6.2 38.0 516 57 15 04 Example LE- 6.4 39.0517 58 16 05 Example LE- 6.1 36.6 516 69 17 06 Example LE- 6.0 41.5 51561 18 07 Example LE- 6.4 40.6 516 63 19 08 Example LE- 6.8 37.8 516 8920 10 C. — 7.2 36.8 516 45 Example 3 C. BCP 7.9 40.2 516 40 Example 4*For lifespan, a measurement was made of time taken for luminance todecrease to 97% of the initial value thereof, using a lifetime testsystem (McScience).

As is understood from the data of Table 5, the organicelectroluminescent elements of Examples 1 to 12, each comprising alifetime enhancement layer in accordance with the present invention,were observed to be superior to those of Comparative Examples 1 and 2 interms of current efficiency, driving voltage and lifespan.

1. An organic electroluminescent element, comprising: an anode; acathode; and an organic layer interposed therebetween, wherein theorganic layer comprises a compound represented by the following Formula1:

wherein, R_(a) and R_(b) are the same or different from each other andare each independently selected from the group consisting of a C₁-C₄₀alkyl group and a C₆-C₆₀ aryl group, or combine with each other to forma fused ring, R₁ to R₃ are the same or different from each other and areeach independently selected from the group consisting of a hydrogen, adeuterium, a halogen, a cyano group, a nitro group, an amino group, aC₁-C₄₀ alkyl group, a C₂-C₄₀ alkenyl group, a C₂-C₄₀ alkynyl group, aC₃-C₄₀ cycloalkyl group, a heterocycloalkyl group having 3 to 40 nuclearatoms, a C₆-C₆₀ aryl group, a heteroaryl group having 5 to 60 nuclearatoms, a C₁-C₄₀ alkyloxy group, a C₆-C₆₀ aryloxy group, a C₁-C₄₀alkylsilyl group, a C₆-C₆₀ arylsilyl group, a C₁-C₄₀ alkylboron group, aC₆-C₆₀ arylboron group, a C₁-C₄₀ phosphine group, a C₁-C₄₀ phosphineoxide group, and a C₆-C₆₀ arylamine group, or each of R₁ to R₃ forms afused ring when combined with an adjacent one, L is selected from thegroup consisting of a single bond, a C₆-C₁₈ arylene group, and aheteroarylene group having 5 to 18 nuclear atoms, Z₁ to Z₅ are the sameor different from each other and are each independently N or C(R₄),provided that at least one of Z₁ to Z₅ is N, and when C(R₄) is presentin a plural number, they are the same or different from each other, cand e are each an integer of 0 to 4, d is an integer of 0 to 3, m and nare each an integer of 1 to 3, R₄ is selected from the group consistingof a hydrogen, a deuterium, a halogen, a cyano group, a nitro group, anamino group, a C₁-C₄₀ alkyl group, a C₂-C₄₀ alkenyl group, a C₂-C₄₀alkynyl group, a C₃-C₄₀ cycloalkyl group, a heterocycloalkyl grouphaving 3 to 40 nuclear atoms, a C₆-C₆₀ aryl group, a heteroaryl grouphaving 5 to 60 nuclear atoms, a C₁-C₄₀ alkyloxy group, a C₆-C₆₀ aryloxygroup, a C₁-C₄₀ alkylsilyl group, a C₆-C₆₀ arylsilyl group, a C₁-C₄₀alkylboron group, a C₆-C₆₀ arylboron group, a C₁-C₄₀ phosphine group, aC₁-C₄₀ phosphine oxide group and a C₆-C₆₀ arylamine group, or bonded toan adjacent substituent to form a fused ring, the alkyl and aryl groupsof R_(a) and R_(b), the alkyl, alkenyl, alkynyl, cycloalkyl,heterocycloalkyl, aryl, heteroaryl, alkyloxy, aryloxy, alkylsilyl,arylsilyl, alkylboron, arylboron, phosphine, phosphine oxide, andarylamine groups of R₁ to R₄, and the arylene and heteroarylene groupsof L may be each independently unsubstituted or substituted with atleast one substituent selected from the group consisting of a deuterium,a halogen, a cyano group, a nitro group, an amino group, a C₁-C₄₀ alkylgroup, a C₂-C₄₀ alkenyl group, a C₂-C₄₀ alkynyl group, a C₃-C₄₀cycloalkyl group, a heterocycloalkyl group having 3 to 40 nuclear atoms,a C₆-C₆₀ aryl group, a heteroaryl group having 5 to 60 nuclear atoms, aC₁-C₄₀ alkyloxy group, a C₆-C₆₀ aryloxy group, a C₁-C₄₀ alkylsilylgroup, a C₆-C₆₀ arylsilyl group, a C₁-C₄₀ alkylboron group, a C₆-C₆₀arylboron group, a C₁-C₄₀ phosphine group, a C₁-C₄₀ phosphine oxidegroup, and a C₆-C₆₀ arylamine group, provided that when the substituentis present in a plural number, they are the same or different from eachother.
 2. The organic electroluminescent element of claim 1, wherein theorganic layer comprises at least one selected form the group consistingof a hole injection layer, a hole transport layer, a light-emittinglayer, a lifetime enhancement layer, an electron transport layer, and anelectron injection layer, and at least one of the lifetime enhancementlayer, the electron transport layer, and the electron injection layercontains the compound represented by Formula
 1. 3. The organicelectroluminescent element of claim 2, wherein the lifetime enhancementlayer contains the compound represented by Formula
 1. 4. The organicelectroluminescent element of claim 3, wherein the light-emitting layercontains a green phosphorescent material and the compound, representedby Formula 1, contained in the lifetime enhancement layer has anionization potential of 6.0 eV or higher and a triplet energy of 2.5 eVor higher.
 5. The organic electroluminescent element of claim 3, whereinthe light-emitting layer contains a blue phosphorescent material and thecompound, represented by Formula 1, contained in the lifetimeenhancement layer has an ionization potential of 6.0 eV or higher and atriplet energy of 2.7 eV or higher.
 6. The organic electroluminescentelement of claim 2, wherein the electron transport layer contains acompound represented by Formula 1, the lifetime enhancement layercontains a compound represented by Formula 1, and the respectivecompounds contained in the electron transport layer and the lifetimeenhancement layer are identical.
 7. The organic electroluminescentelement of claim 2, wherein the electron injection layer contains acompound represented by Formula 1, the lifetime enhancement layercontains a compound represented by Formula 1, and the respectivecompounds contained in the electron injection layer and the lifetimeenhancement layer are identical.
 8. The organic electroluminescentelement of claim 1, wherein the compound represented by Formula 1 has anionization potential of 5.5 eV or higher, a gap between HOMO and LUMO ofgreater than 3.0 eV, a triplet energy of 2.3 eV or higher, and a gapbetween singlet energy and triplet energy of less than 0.7 eV.
 9. Theorganic electroluminescent element of claim 1, wherein the compoundrepresented by Formula 1 has a hole motility of 1×10⁻⁶ cm^(z)/V·s orgreater and an electron motility of 1×10⁻⁶ cm^(z)/V·s or greater at roomtemperature
 10. The organic electroluminescent element of claim 1,wherein the compound represented by Formula 1 is selected from the groupconsisting of respective compounds represented by the following Formulas2 to 4:

wherein, R_(a), R_(b), R₁ to R₃, Z₁ to Z₅, c, d, and e are each the sameas defined in claim
 1. 11. The organic electroluminescent element ofclaim 1, wherein the structure (substituent) represented by

(* is a site where to bond with L) in Formula 1 is selected from thegroup consisting of the structures represented by the following C-1 toC-15:

wherein, R₄ is the same as defined in claim 1, R₅ is selected from thegroup consisting of a hydrogen, a deuterium, a halogen, a cyano group, anitro group, a C₁-C₄₀ alkyl group, a C₂-C₄₀ alkenyl group, a C₂-C₄₀alkynyl group, a C₃-C₄₀ cycloalkyl group, a heterocycloalkyl grouphaving 3 to 40 nuclear atoms, a C₆-C₆₀ aryl group, a heteroaryl grouphaving 5 to 60 nuclear atoms, a C₆-C₆₀ aryloxy group, a C₁-C₄₀ alkyloxygroup, a C₆-C₆₀ arylamine group, a C₁-C₄₀ alkylsilyl group, a C₁-C₄₀alkylboron group, a C₆-C₆₀ arylboron group, a C₆-C₆₀ arylphosphinegroup, a C₆-C₆₀ arylphosphine oxide group, and a C₆-C₆₀ arylsilyl group,or bonded to an adjacent substituent to form a fused ring, and p is aninteger of 1 to 4, the alkyl, alkenyl, alkynyl, cycloalkyl,heterocycloalkyl, aryl, heteroaryl, aryloxy, alkyloxy, arylamine,alkylsilyl, alkylboron, arylboron, arylphosphine, arylphosphine oxideand arylsilyl groups of R₅ may be each independently unsubstituted orsubstituted with at least one substituent selected from the groupconsisting of a deuterium, a halogen, a cyano group, a nitro group, aC₁-C₄₀ alkyl group, a C₂-C₄₀ alkenyl group, a C₂-C₄₀ alkynyl group, aC₆-C₆₀ aryl group, a heteroaryl group having 5 to 60 nuclear atoms, aC₆-C₆₀ aryloxy group, a C₁-C₄₀ alkyloxy group, a C₆-C₆₀ aryl aminegroup, a C₃-C₄₀ cycloalkyl group, a heterocycloalkyl group having 3 to40 nuclear atoms, a C₁-C₄₀ alkylsilyl group, a C₁-C₄₀ alkylboron group,a C₆-C₆₀ arylboron group, a C₆-C₆₀ arylphosphine group, a C₆-C₆₀arylphosphine oxide group, and a C₆-C₆₀ arylsilyl group, provided thatwhen the substituent is present in a plural number, they are the same ordifferent from each other.
 12. The organic electroluminescent element ofclaim 11, wherein the compound represented by Formula 1 is a compoundrepresented by the following Formula 5:

wherein, R_(a), R_(b), R₁ to R₄, L, c, d, e, m, and n are each the sameas defined in claim
 1. 13. The organic electroluminescent element ofclaim 12, wherein R₄'s are identical.
 14. The organic electroluminescentelement of claim 1, wherein R_(a) and R_(b) are the same or differentfrom each other and are each independently a methyl group or a phenylgroup or bond each other to form a fused ring represented by

is a site where to bond).
 15. The organic electroluminescent element ofclaim 1, wherein L is selected from the group consisting of thestructures represented by the following L-1 to L-9 (* is a site where tobond):


16. The organic electroluminescent element of claim 1, wherein thecompound represented by Formula 1 is selected from the group consistingcompounds represented by the following Formulas LE-01 to LE-12: